<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>ajax基础回顾</title>
	</head>
	<body>
		<script type="text/javascript">
			var xhr = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject('Microsoft.XMLHTTP')
			xhr.open('GET','test.php')
			xhr.send()
			xhr.onreadystatechange = function() {
				if(this.readyState !== 4) return;
				console.log(this)
			}
		</script>
	</body>
</html>
